Dear Doctors: My older brother worked construction his whole life, and now he has bad arthritis in his left hip. He was in enough pain that he finally saw his doctor about it. Instead of a hip replacement, they want to do hip resurfacing. What is that? Will it be as effective?
Dear Reader: Hip resurfacing is a type of hip-replacement surgery.
The most common reason someone needs this type of surgery is advanced osteoarthritis. Also known as “wear-and-tear arthritis,” it is common in older adults and among certain professions.
Osteoarthritis of the hip can cause pain severe enough to limit mobility and interfere with daily activities.
The hip is a ball-and-socket joint, which allows for the range of motion we have in our legs. The rounded top of the femur, the larger leg bone, forms the ball. This is the femoral head. It fits into a cuplike socket in the pelvis, the acetabulum. Both ball and socket are covered with smooth cartilage, which allows them to glide painlessly against each other.
With osteoarthritis, that cartilage gradually wears away, making movement painful.
When nonsurgical approaches to managing osteoarthritis pain aren’t successful, hip-replacement surgery is often recommended.
In a traditional hip replacement, the femoral head and acetabulum are removed, replaced with components made of plastic, ceramic and sometimes metal.
With hip resurfacing, damaged bone and cartilage from the femoral head and acetabulum are trimmed away. The surgeon then lines the socket with a metal shell and covers the femoral head with a smooth metal cap.
The advantages over total hip replacement include more rapid recovery, improved mobility and decreased risk of hip dislocation. It’s also easier to exchange implants if they wear out or fail.
But there are drawbacks. One is the risk of a femoral neck fracture, which occurs in a small number of hip resurfacing patients. This necessitates a complete hip replacement. The other is called metal ion risk. Because hip resurfacing uses two metal components, the resulting friction can, over time, lead to the release of tiny metal molecules that can cause pain and swelling, which can require more surgery.
The ions can also move throughout the body via the bloodstream and have been associated with adverse effects to the heart, nervous system and thyroid and cancer. Metal ion risk is a potential complication in traditional hip replacements that use a metal ball and a metal socket.
Dr. Eve Glazier and Dr. Elizabeth Ko are internists at UCLA Health.
